Hi,
On 6/10/21 1:55 PM, Joonas Lahtinen wrote:
> (Address for Hans was corrupt in previous message, which confused my mail
> client. Sorry for duplicate message, the other is without From: field).
>
> + Jesse
>
> Quoting Colin Ian King (2021-06-09 14:50:07)
>> Hi,
>>
>> I was reviewing some old unassigned variable warnings from static
>> analysis by Coverity and found an issue introduced with the following
>> commit:
>>
>> commit aa7ffc01d254c91a36bf854d57a14049c6134c72
>> Author: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
>> Date: Fri May 14 15:41:14 2010 -0700
>>
>> x86 platform driver: intelligent power sharing driver
>>
>> The analysis is as follows:
>>
>> drivers/platform/x86/intel_ips.c
>>
>> 871 static u32 get_cpu_power(struct ips_driver *ips, u32 *last, int period)
>> 872 {
>> 873 u32 val;
>> 874 u32 ret;
>> 875
>> 876 /*
>> 877 * CEC is in joules/65535. Take difference over time to
>> 878 * get watts.
>> 879 */
>> 880 val = thm_readl(THM_CEC);
>> 881
>> 882 /* period is in ms and we want mW */
>> 883 ret = (((val - *last) * 1000) / period);
>>
>> Unused value (UNUSED_VALUE)
>> assigned_value: Assigning value from ret * 1000U / 65535U to ret here,
>> but that stored value is not used.
>>
>> 884 ret = (ret * 1000) / 65535;
>> 885 *last = val;
>> 886
>> 887 return 0;
>> 888 }
>>
>> I'm really not sure why ret is being calculated on lines 883,884 and not
>> being used. Should that be *last = ret on line 885? Looks suspect anyhow.
This has already been fixed (yesterday actually) in linux-next:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/commit/?h=for-next&id=13c3b4f76073d73dd81e418295902676153f6cb5
Regards,
Hans
